Film/substrate registry as measured by anomalous x-ray scattering at a reacted, epitaxial Cu/Si(111) interface

We used anomalous x-ray-diffraction methods to measure the contribution of an epitaxial copper overlayer on silicon to the crystal truncation rods (CTR's). The intensities of the CTR's are analyzed to determine interface structure; the epitaxy of a large-misfit system, Cu on Si(111), can be described in relationship to this structure. Anomalous scattering observed at the Cu K edge along a Si CTR demonstrates copper atoms to be in registry with the Si(111) surface. The copper-atom registry at the interface can be modeled based on the known bulk {η}-Cu₃Si structure and observed epitaxy.